No way Nishikori is winning a slam unless the current top 4 go into retirement for the next 5 years. He's also not that young at 23. I really wonder sometimes if people think before they start these threads. In the current example, I am sure that did not happen but there are other reasons for that.
When Nole and Murray are 30, Nishikori will be 28, not exactly a world of a difference. Also Del Potro >>>>> Raonic/Nishikori.
You really think the top 4 guys, especially Rafole still hanging around for another 5+ years, given how physical their games are?
Anyways what about Rafter? He began to peak around mid-late 20's. Include a pretty weak future for the rest of the field, and the outcome just seems inevitable. I just don't see anyone else who can grab slams, besides these two youngsters. Yes, Del Potro could also be in the mix as well. I think it would be nice to see either guys holding up the Wimby and USO trophies. When Nadal retires, we'll start to see surprise winners for RG since clay aren't probably Kei's and Milo's best surfaces. That would be pretty cool I think. But I can bet you my ass that a Spanish player would still at least grab one RG in this new era.